This was back in December 2015, and the hapless Browns went on to lose, 17-13, of course. It was the first of five times the 6-foot, 207-pound Manziel would be hit behind the line of scrimmage, as he not only struggled to throw with anticipation and accuracy — he completed only 13 of 32 passes for 136 yards and an interception — but also took a beating doing it.

Oh yes, Manziel did some Johnny Football things that day, using his trademark break-neck, Fran Tarkenton-ish scrambles to rush 11 times for 108 yards. And at times that was entertaining to watch, as he repeatedly dodged tacklers, all while holding the ball like a loaf of bread. But in the process, he absorbed seven additional hits, and as his ball placement seemingly got worse with every shot, it slowly became clear that Manziel’s one-sided reliance on his creativity outside the pocket (one of his greatest strengths in college) had become a liability in the NFL.

“We wanted to let him run around, then go hit him,” a member of the Chiefs recently told Yahoo Sports. “We beat him up so bad he couldn’t practice next week.”

Indeed. Manziel never practiced with the Browns again, as he sat out the next game with a concussion and was eventually released two months later. His subsequent struggles with addiction, bipolar disorder and legal issues are well-documented, but America loves a great redemption story, and NFL decision-makers are not immune to that, especially when it involves a talented former first-rounder with an exciting style of play, and a Heisman pedigree who is not yet 26 years old.

Former NFL quarterback and Heisman winner Johnny Manziel is trying to resume his football career in the CFL with the Hamilton Tiger-Cats. (AP)

So rest assured, when Manziel took the first step toward potentially returning to the NFL this April, when he completed 19 of 31 passes for 271 yards, a touchdown and an interception (while running for two more scores) in two games of the Spring League, there were plenty of NFL eyes watching. And when Manziel agreed to a two-year contract with the Hamilton Tiger-Cats of the Canadian Football League over the weekend, even more took note, because let’s face it: quarterbacks with strong arms, athleticism and a proven ability to ad-lib on the fly don’t exactly grow on trees.

“His game fits some of the things teams are doing now,” one NFL decision-maker told Yahoo Sports. “Good QBs are hard to find.”

Still, a handful of NFL evaluators polled by Yahoo Sports agreed that even if Manziel initially wins the starting job for Hamilton — which is no sure thing, as the presumptive No. 1 quarterback, Jeremiah Masoli, started 12 of 18 games there last year — he will likely need to have at least one, realistically two, productive and drama-free seasons in the CFL before an NFL team feels comfortable bringing him in. Their biggest concern, obviously, is his maturity, which hampered his preparation during his two years in Cleveland and was a distraction for the Browns.

“He probably needs a few years of good football, combined with zero off-field issues,” one decision-maker said.

“He needs to show that he is committed, and a changed person,” another added.

“Go play in Canada and show you can play,” one league source said, who also wondered if Manziel’s pride would allow him to put in the necessary work to improve.

And therein lies the rub. Because all the evaluators added that before he returns to the NFL, Manziel must also show an improved ability to throw from the pocket, which would not only keep NFL defenses honest and prevent them from keying on his scrambling like the Chiefs did in his final appearance, but also help him preserve his smallish frame in a league full of behemoths.

“If Manziel’s first receivers weren’t open, he was gone, out the pocket,” one evaluator told Yahoo Sports. “He’s got to learn to play in the pocket, and that is a big adjustment, and it’s going to take some time. He gets in there trying to play the same way, and he’ll be another [Robert Griffin III] — banged up and hurt.”

Johnny Manziel could use his stint in the CFL to prove he’s still good enough for the NFL, with several team executives hoping he matures on and off the field. (AP)

Hamilton’s offense fits Manziel. He’s playing for longtime coach June Jones (his resume includes coaching jobs in the NFL from 1987-1998), who’s running a pass-happy spread that provided Masoli chances to also rush for nearly 500 yards. But even though the field is wider in the CFL, which makes for a more open game, it’s primarily a passing league because teams have only three downs to get 10 yards as opposed to four, meaning Manziel will conceivably have plenty of opportunities to work on his pocket passing if he nails down the job.

Manziel has never been known as a tape fiend, let alone someone particularly obsessive about fundamentals. But some around the league wonder whether his on-field competitiveness and mental toughness — which one evaluator even compared to 2018 No. 1 overall pick Baker Mayfield’s — will finally begin to manifest itself in his weekly work habits if he’s indeed got his life together.

“I felt like he could make it three years ago,” one decision-maker said. “Obviously the off-field issues got in the way of his preparation.”

If everything goes well in Canada, there’s certainly a sense that Manziel can play in the NFL as a backup and be a change-of-pace guy who comes in, shakes things up and makes some plays. That’s what some scouts and executives had him pegged as coming out of the 2014 draft, anyway. And if things go really well — meaning he’s indeed grown up, and his game has grown along with it — maybe he can be more than that. You never really know in football.

In the meantime, teams will keep tabs on him from afar, knowing that until they see prolonged, tangible growth and results, they’ll likely be wise to remain skeptical.

“He just needs to go all in and start from ground zero,” one decision-maker said.